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  1. AK6DN

    Dec 4000 VLC

    I have a couple of VAX 4000 VLC boxes. Both started misbehaving a bit recently (run for a while then reboot). Noticed the boxes were getting really warm. Opened them up, and found the fans on the power supplies had stopped rotating. Boxes ran fine opened with external fan blowing into the power...
  2. AK6DN

    Problems booting PDP-11 through tu58 emulator

    It does, but they are contained within TU58 (or RX02) XXDP .DSK images files. One could use my xxdpdir.pl program to extract all the files from an XXDP image (available here: https://github.com/AK6DN/xxdpdir I use that program to extract all the files from the RL02 distribution media and then...
  3. AK6DN

    COS310/WPS278 floppy images?

    So this is completely different than how an RX01/RX02 drive itself implements 12b vs 8b mode storage on RX01 or RX02 media. In 12bit mode in the RX drive controller, each three consecutive 8bit media storage bytes (totaling 24bits) is then used to store two 12bit words. Only 3/4 of the media...
  4. AK6DN

    COS310/WPS278 floppy images?

    Re: RX01/02 sector ordering: http://gunkies.org/wiki/RX01/02_floppy_drive#Layout
  5. AK6DN

    TK50 emulator

    Someone could certainly develop a new microcode file for the ZuluSCSI (or even SCSI2SD I guess) and you could just drop a new SCSI tape emulator .bin fine on the SD card and away you go. The full sources are here: https://github.com/ZuluSCSI/ZuluSCSI-firmware for the SCSI disk support. Just...
  6. AK6DN

    D662/D664 Diode Replacements?

    The 1N645-1 at DigiKey is a current production part from MicroChip (MicroSemi subdivision), so its lineage is not an issue. Or 1N645 from NTE at DigiKey: https://www.digikey.com/en/products/detail/nte-electronics,-inc/1N645/11644785 for US$2.22 each. The 1N3606 however appears to be...
  7. AK6DN

    D662/D664 Diode Replacements?

    Have this document from ages ago ... DEC EIE D-003, D003 1N994 D-662, D662 1N645 D-664, D664 1N3606 D-668, D668 Two 1N3606 in series D-670, D670 1N3653 D-671, D671 1N3653 D-672, D672 1N3653 DEC 999...
  8. AK6DN

    Are Unibus and Qbus fingers mechanically/electrically compatible?

    DEC used the same edge card connector finger design of 18 connections, double sided, 36 connections per blade very early on. Starting with the individual one blade and two blade flip chip modules, thru the two/four/six blade UNIBUS, QBUS, and OMNIBUS modules. They are all mechanically...
  9. AK6DN

    Problems booting PDP-11 through tu58 emulator

    For reference, here is a boot using the M9312 DD boot prom on my 11/34, booting an XXDP bootable image. I enabled detailed debug mode via the -d switch to expose all the gory details. dec[503] tu58em -v -d -p 5 -s 115200 -r pdp11/image_tu58/1134_1.DSK info: unit 0 r file...
  10. AK6DN

    Problems booting PDP-11 through tu58 emulator

    From my github TU58EM example, here is what you should expect: E:\DEC> tu58em -p 3 -s 38400 -r boot.dsk info: unit 0 r file 'boot.dsk' info: serial port 3 at 38400 baud 1 stop info: TU58 start info: R restart, S toggle send init, V toggle verbose, D toggle debug, Q quit info: TU58 emulator...
  11. AK6DN

    Problems booting PDP-11 through tu58 emulator

    Look at the README here ... https://github.com/AK6DN/tu58em A long (now) time ago I tested FTDI and PROLIFIC USB serial adapters along with a real COM port on a PC. The real COM port and the FTDI h/w+drivers handled the BREAK condition correctly; the PROLIFIC h/w+driver did not. It was an...
  12. AK6DN

    Problems booting PDP-11 through tu58 emulator

    Classic display when there is a serial port issue. Mismatch in configured baud rate or stop bits. Unreliable serial interface operation. The 11xx_1.dsk should boot on your system. All the TU58 images in that location are bootable XXDP images. What TU58 bootstrap are you using? You don't...
  13. AK6DN

    Anyone able to swap Full Height SCSI out with SCSI2SD?

    IDK I moved on from SCSI2SD to using the ZuluSCSI, RP2040 version. Very much like it both functionally and performance-wise. Have never used the bluescsi board. Read here: https://forum.vcfed.org/index.php?threads/scsi-sd-card-adapter-for-emulex-qbus-card.1245327/
  14. AK6DN

    Building a PDP-11 from scratch

    "attempt to build a motherboard (how many layers this monster will be ? no idea)" just kind of noted in passing at the end of the list... All the logic boards are the smallest part of the problem and the technologically easiest part. The backplane in the 11/70 was a two piece wire-wrapped...
  15. AK6DN

    yet another PDP-11 barebone hack

    Even the lowly 11/05 implements the console switch functions in microcode.
  16. AK6DN

    orange tantalum (?) caps in DEC equipment

    Appears to be similar this this style of solid tantalum device ... https://uk.rs-online.com/web/p/tantalum-capacitors/7990054
  17. AK6DN

    SCSI SD card adapter for Emulex Qbus card?

    Already gave my unused scsi2SD controllers away.
  18. AK6DN

    RK05 disk emulator development and discussion

    Got it. You are making a tradeoff in the design of your controller to simplify it at the expense of preprocessing disk images for use with it. But you could compute the track/sector numbers from the position of the data block in the file, correct? And vice versa to go from a track/sector...
  19. AK6DN

    RK05 disk emulator development and discussion

    Have you guys not followed the fiasco that happened with SIMH around adding/extending metadata within legacy disk images? Upshot is fooling around with the disk data image, either prepending or appending arbitrary metadata within the file itself is highly frowned up. Add a separate companion...
  20. AK6DN

    Problems booting PDP-11 through tu58 emulator

    It was, but I am not suggesting that is the norm. This was a special case where I needed/wanted to test the removed chip functionality on a separate test fixture. The normal means of just cutting the pins off flush with the body (making for maximum length pins left in the PCB for easier removal)...